System and method for controlling shift of hybrid vehicle

ABSTRACT

A system and a method for controlling shifting stage of a hybrid vehicle may include a speed detecting device that detects a vehicle speed, an automatic transmission that changes a shifting stage of the vehicle, and a shift controller connected to the speed detecting device and the automatic transmission. The shift controller is configured to determine a start of shift control based on a travel environment and a travel state of the vehicle, compares the vehicle speed with a target vehicle speed when the start of the shift control is determined, and performs the shift control based on a state of charge of a battery of the vehicle and a regenerative braking amount of the vehicle when the shift controller concludes that the vehicle speed exceeds the target vehicle speed.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2021-0030007, filed on Mar. 8, 2021, the entire contents of which isincorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a system and a method for controllingshifting stage of a hybrid vehicle.

Description of Related Art

In general, an automatic transmission allows an optimal shifting stageto be automatically implemented based on a vehicle travel situation suchas an accelerator pedal position, a vehicle speed, and the like. When avehicle coasts before reaching a target point, an existing automatictransmission predicts a deceleration profile for each shifting stage toallow the vehicle to travel with a shifting stage which is mostadvantageous for fuel economy while satisfying a target vehicle speedwhen passing the target point.

The information disclosed in this Background of the Invention section isonly for enhancement of understanding of the general background of theinvention and may not be taken as an acknowledgement or any form ofsuggestion that this information forms the prior art already known to aperson skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing asystem and a method for controlling shifting stage of a hybrid vehiclethat complexly control a shifting stage, a regenerative braking amount,and an engine brake such that a vehicle speed may reach a target vehiclespeed.

The technical problems to be solved by the present inventive concept arenot limited to the aforementioned problems, and any other technicalproblems not mentioned herein will be clearly understood from thefollowing description by those skilled in the art to which variousexemplary embodiments of the present invention pertains.

According to various aspects of the present invention, a system forcontrolling shifting stage of a hybrid vehicle includes a speeddetecting device that detects a vehicle speed, an automatic transmissionthat changes a shifting stage of the vehicle, and a shift controllerelectrically connected to the speed detecting device and the automatictransmission, and the shift controller is configured to determine astart of shift control based on a travel environment and a travel stateof the vehicle, compares the vehicle speed with a target vehicle speedwhen the start of the shift control is determined, and performs theshift control based on a state of charge of a battery of the vehicle anda regenerative braking amount of the vehicle when the shift controllerconcludes that the vehicle speed exceeds the target vehicle speed.

In various exemplary embodiments of the present invention, the shiftcontroller may recognize an overspeed monitoring location in front ofthe vehicle based on a vehicle location or the overspeed monitoringlocation received from a navigation device, set the overspeed monitoringlocation in front of the vehicle as a target location, determine whetherthe vehicle is coasting according to a position of an accelerator pedalmeasured by an accelerator position sensor, and determine to starttarget location-based shift control when the vehicle is coasting towardthe target location.

In various exemplary embodiments of the present invention, the shiftcontroller may compare the state of charge of the battery with areference state of charge of the battery, compare the regenerativebraking amount with a maximum regenerative braking amount when the stateof charge of the battery is less than the reference SOC value of thebattery, and change a current stage of the shifting stage to a lowerstage when the shift controller concludes that the regenerative brakingamount is equal to or greater than the maximum regenerative brakingamount.

In various exemplary embodiments of the present invention, the maximumregenerative braking amount may be set based on a motor capacity and abattery capacity.

In various exemplary embodiments of the present invention, the shiftcontroller may be configured to determine a motor regenerative torqueaccording to the changed shifting stage after the shifting stage ischanged.

In various exemplary embodiments of the present invention, the shiftcontroller may compare the state of charge of the battery with areference state of charge of the battery, compare the regenerativebraking amount with a maximum regenerative braking amount when the stateof charge of the battery is less than the reference SOC value of thebattery, and increase a motor regeneration amount by a specificregeneration amount when the regenerative braking amount is less thanthe maximum regenerative braking amount.

In various exemplary embodiments of the present invention, the specificregeneration amount may be tuned based on a distance between the vehiclelocation and the target location and the vehicle speed.

In various exemplary embodiments of the present invention, the shiftcontroller may perform the shift control using an engine brake when thestate of charge of the battery is equal to or greater than the referenceSOC value of the battery.

According to various aspects of the present invention, a method forcontrolling shifting stage of a hybrid vehicle includes determining astart of shift control based on a travel environment and a travel stateof the vehicle, comparing a vehicle speed with a target vehicle speedwhen the start of the shift control is determined, and performing theshift control based on a state of charge of a battery of the vehicle anda regenerative braking amount of the vehicle when the shift controllerconcludes that the vehicle speed exceeds the target vehicle speed.

In various exemplary embodiments of the present invention, thedetermining to start the shift control may include recognizing anoverspeed monitoring location in front of the vehicle based on a vehiclelocation or the overspeed monitoring location received from a navigationdevice, and setting the overspeed monitoring location in front of thevehicle as a target location, determining whether the vehicle iscoasting according to a position of an accelerator pedal measured by anaccelerator position sensor, and determining to start targetlocation-based shift control when the vehicle is coasting toward thetarget location.

In various exemplary embodiments of the present invention, theperforming of the shift control may include comparing the state ofcharge of the battery with a reference state of charge of the battery,comparing the regenerative braking amount with a maximum regenerativebraking amount when the state of charge of the battery is less than thereference SOC value of the battery, and changing a current stage of theshifting stage to a lower stage when the shift controller concludes thatthe regenerative braking amount is equal to or greater than the maximumregenerative braking amount.

In various exemplary embodiments of the present invention, the maximumregenerative braking amount may be set based on a motor capacity and abattery capacity.

In various exemplary embodiments of the present invention, theperforming of the shift control may further include determining a motorregenerative torque according to the changed shifting stage after theshifting stage is changed.

In various exemplary embodiments of the present invention, theperforming of the shift control may further include comparing the stateof charge of the battery with a reference state of charge of thebattery, comparing the regenerative braking amount with a maximumregenerative braking amount when the state of charge of the battery isless than the reference SOC value of the battery, and increasing a motorregeneration amount by a specific regeneration amount when theregenerative braking amount is less than the maximum regenerativebraking amount.

In various exemplary embodiments of the present invention, the specificregeneration amount may be tuned based on a distance between the vehiclelocation and the target location and the vehicle speed.

In various exemplary embodiments of the present invention, theperforming of the shift control may further include performing the shiftcontrol using an engine brake when the state of charge of the battery isequal to or greater than the reference SOC value of the battery.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description, which together serve to explaincertain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a hybrid vehicle related to thepresent invention;

FIG. 2 is a block diagram illustrating a system for controlling shiftingstage of a hybrid vehicle according to exemplary embodiments of thepresent invention;

FIG. 3 is a flowchart illustrating a method for controlling shiftingstage of a hybrid vehicle according to exemplary embodiments of thepresent invention;

FIG. 4 is a graph illustrating a change in a vehicle speed according tovarious exemplary embodiments of the present invention; and

FIG. 5 is a block diagram illustrating a computing system executing ashift control method according to exemplary embodiments of the presentinvention.

It may be understood that the appended drawings are not necessarily toscale, presenting a somewhat simplified representation of variousfeatures illustrative of the basic principles of the present invention.The specific design features of the present invention as includedherein, including, for example, specific dimensions, orientations,locations, and shapes will be determined in part by the particularlyintended application and use environment.

In the figures, reference numbers refer to the same or equivalent partsof the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the presentinvention(s) will be described in conjunction with exemplary embodimentsof the present invention, it will be understood that the presentdescription is not intended to limit the present invention(s) to thoseexemplary embodiments. On the other hand, the present invention(s)is/are intended to cover not only the exemplary embodiments of thepresent invention, but also various alternatives, modifications,equivalents and other embodiments, which may be included within thespirit and scope of the present invention as defined by the appendedclaims.

Hereinafter, various exemplary embodiments of the present invention willbe described in detail with reference to the exemplary drawings. Inadding the reference numerals to the components of each drawing, itshould be noted that the identical or equivalent component is designatedby the identical numeral even when they are displayed on other drawings.Furthermore, in describing the exemplary embodiment of the presentinvention, a detailed description of the related known configuration orfunction will be omitted when it is determined that it interferes withthe understanding of the exemplary embodiment of the present invention.

In describing the components of the exemplary embodiment according tovarious exemplary embodiments of the present invention, terms such asfirst, second, A, B, (a), (b), and the like may be used. These terms aremerely intended to distinguish the components from other components, andthe terms do not limit the nature, order or sequence of the components.Unless otherwise defined, all terms including technical and scientificterms used herein have the same meaning as commonly understood by one ofordinary skill in the art to which the present disclosure belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning which isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 is a block diagram illustrating a hybrid vehicle related to thepresent invention.

A hybrid vehicle is a vehicle that utilizes two or more differentdriving sources, and generally refers to a vehicle driven by an enginethat generates a driving force by burning fuel and a motor thatgenerates the driving force with electrical energy of a battery. Forexample, there are a hybrid electric vehicle (HEV) and a plug-in hybridelectric vehicle (PHEV). Referring to FIG. 1 , the hybrid vehicle mayinclude an engine 10, a hybrid starter generator (HSG) 20, a clutch 30,a motor 40, a transmission 50, and the like.

The engine 10 may generate power (an engine torque) required to drivethe vehicle by burning the fuel. As the engine 10, various known enginessuch as a gasoline engine, a diesel engine, or the like may be used. Theengine 10 may control an output torque (that is, an engine torque) inresponse to a command of an engine management system (EMS).

The HSG 20 may be mounted on the engine 10 to start the engine 10 bycranking the engine 10. The HSG 20 may play a key role of starting theengine when switching from an electric vehicle mode to a hybrid mode inwhich the engine 10 and the motor 40 operate together. The HSG 20 maygenerate the electrical energy by operating as a generator in a state inwhich the engine 10 is started. The electrical energy generated by theHSG 20 may be used to charge a battery “B”.

The clutch 30 may be disposed between the engine 10 and the motor 40 toregulate the power (the output torque) of the engine 10. The clutch 30may transmit, to a driving wheel (a wheel), or block the power (theengine torque) generated by the engine 10 through engagement ordisengagement.

The motor 40 may receive electric power from the battery “B” to generatethe power (motor power) and transmit the power to the driving wheel. Themotor 40 may control the output torque (a motor torque) of the motor 40by changing a rotation direction and revolutions per minute (RPM) inresponse to instruction of a motor control unit (MCU). The motor 40 maybe used as a generator for charging the battery “B” by generating acounter electro-motive force when a state of charge (SOC) of the batteryis insufficient or during regenerative braking. The battery “B” isconfigured to supply electric power required for driving the vehicle,which may be implemented as a high voltage battery. A power convertermay be disposed between the motor 40 and the battery “B”. The powerconverter may convert a voltage output from the battery “B” into a motordriving voltage and supply the motor driving voltage. The battery “B”may be charged by regenerative energy generated from the motor 40.

The transmission 50 may output the motor torque or a value obtained byconverting the engine torque and the motor torque in a shift ratiomatching a shifting stage (a gear stage). The transmission 50 may changethe shifting stage in response to instruction of a transmission controlunit (TCU). The TCU may determine the optimal shifting stage based oninformation such as a travel speed of the vehicle (that is, a vehiclespeed or a wheel speed), a position of an acceleration pedal, an enginerevolution per minute, and/or clutch travel through sensors in thevehicle.

FIG. 2 is a block diagram illustrating a system for controlling shiftingstage of a hybrid vehicle according to exemplary embodiments of thepresent invention.

Referring to FIG. 2 , a system 100 for controlling shifting stage of thehybrid vehicle may include a navigation device 110 connected through avehicle network and/or a wireless network, a speed detecting device 120,an accelerator position sensor (APS) 130, storage 140, an automatictransmission 150, a vehicle controller 160, a shift controller (TCU)170, and the like. The vehicle network may be implemented as acontroller area network (CAN), a media oriented systems transport (MOST)network, a local interconnect network (LIN), an ethernet, and/or aX-by-Wire (Flexray). As the wireless network, a Wi-Fi, a Bluetooth, anear field communication (NFC), a radio frequency identification (RFID),an infrared data association (IrDA), and/or a ZigBee may be used.

When a destination is set, the navigation device 110 may navigate andguide a travel route to the destination. The navigation device 110 maysearch for an optimal route (e.g., a shortest distance and/or a minimumtime) by reflecting real-time traffic information when searching for thetravel route. Although not shown in the drawing, the navigation device110 may include a memory for storing map data, a global positioningsystem (GPS) receiver for measuring a vehicle location, a communicationmodule for receiving the traffic information from outside, and/or aprocessor for searching for the travel route and guiding a route alongthe searched travel route.

The navigation device 110 may transmit information such as the travelroute, road information (e.g., a speed limit and the like), the vehiclelocation, and/or an overspeed monitoring location to the shiftcontroller 170. In the present connection, the overspeed monitoringlocation may be a location of an overspeed monitoring camera installedto regulate an overspeeding vehicle.

The speed detecting device 120 may detect a current vehicle speed (thevehicle speed). The speed detecting device 120 may measure the vehiclespeed using a wheel speed sensor, a vehicle speed sensor, or the like.Furthermore, the speed detecting device 120 may receive vehicle speedinformation from the navigation device 110, the vehicle controller 160,a cluster, or the like.

The accelerator position sensor 130 may measure the position of theaccelerator pedal. The accelerator position sensor 130 may convert anamount of stepping on the accelerator pedal into a voltage and outputthe voltage.

The storage 140 may store information (data) received from thenavigation device 110, information output from the speed detectingdevice 120 and the accelerator position sensor 130, and data inputand/or output in response to operations of the vehicle controller 160and the shift controller 170. The storage 140 may store a decelerationprofile for each shifting stage. The storage 140 may include at leastone of storage media (recording media) of a flash memory, a hard disk, asolid state disk (SSD), a secure digital card (SD card), a random accessmemory (RAM), a static random access memory (SRAM), a read only memory(ROM), a programmable read only memory (PROM), an electrically erasableand programmable ROM (EEPROM), and/or an erasable and programmable ROM(EPROM).

The automatic transmission 150 may output the motor torque or the valueobtained by converting the engine torque and the motor torque in theshift ratio matching the shifting stage. The automatic transmission 150may automatically change the shifting stage in response to instructionof the shift controller 170.

The vehicle controller 160 may control overall operations of the hybridvehicle. The vehicle controller 160 may receive a current shiftingstage, a motor regeneration amount (regenerative energy), and the likefrom the shift controller 170. The vehicle controller 160 may monitorthe state of charge (SOC) of the battery through communication with abattery management system (BMS). The vehicle controller 160 may transmitthe state of charge of the battery and a maximum regeneration amount tothe shift controller 170.

The shift controller 170 may collect the information such as the vehiclespeed, the position of the accelerator pedal, and the like through thespeed detecting device 120 and the accelerator position sensor 130. Theshift controller 170 may determine the optimal shifting stage based onthe information such as the vehicle speed, the position of theacceleration pedal, and the like. The shift controller 170 may instructthe automatic transmission 150 to change to the determined shiftingstage. The shift controller 170 may transmit the information on theshifting stage and the motor regeneration amount to the vehiclecontroller 160. The shift controller 170 may receive the information onthe state of charge (SOC) of the battery and the maximum motorregeneration amount (a maximum regenerative braking amount) from thevehicle controller 160.

Each of the vehicle controller 160 and the shift controller 170 mayinclude at least one processor. The processor may be implemented as atleast one processing device of an application specific integratedcircuit (ASIC), a digital signal processor (DSP), a programmable logicdevice (PLD), a field programmable gate array (FPGA), a centralprocessing unit (CPU), a microcontroller, and/or a microprocessor.Furthermore, each controller 160 or 170 may include a memory locatedinside and/or outside the processor. The memory may be a non-transitorystorage medium that stores instructions executed by the processor. Thememory may be a random access memory (RAM), a static random accessmemory (SRAM), a read only memory (ROM), a programmable read only memory(PROM), an electrically erasable and programmable ROM (EEPROM), and/oran erasable and programmable ROM (EPROM).

The shift controller 170 may recognize an overspeed monitoring locationlocated in front of the vehicle based on the travel route, the vehiclelocation, or the overspeed monitoring location received from thenavigation device 110. For example, the shift controller 170 mayrecognize an overspeed monitoring location located within 500 m of thevehicle ahead by comparing the vehicle location and the overspeedmonitoring location with each other based on the travel route.Furthermore, the shift controller 170 may recognize the overspeedmonitoring location by detecting an overspeed monitoring camerainstalled in the front using a camera or the like mounted on thevehicle. The shift controller 170 may set the recognized overspeedmonitoring location as a target location.

The shift controller 170 may determine whether the vehicle is coastingusing the accelerator position sensor 130. The shift controller 170 maydetermine that the vehicle is coasting when a driver does not step onthe acceleration pedal.

The shift controller 170 may determine to start target location-basedshift control when the vehicle is coasting toward the target location.The shift controller 170 may predict the deceleration profile for eachshifting stage during the coasting, and determine the optimal shiftingstage for the vehicle speed to reach the target vehicle speed based onthe predicted deceleration profile for each shifting stage when passingthe target location. The shift controller 170 may determine not to startthe target location-based shift control when the overspeed monitoringlocation is recognized, but the vehicle is not coasting.

The shift controller 170 may compare the current vehicle speed with thetarget vehicle speed when it is determined to start the shift control.The shift controller 170 may acquire the current vehicle speed using thespeed detecting device 120. The shift controller 170 may set a speedlimit set at the overspeed monitoring location (the target location) asthe target vehicle speed. That is, the shift controller 170 may set aspeed limit set in the overspeed monitoring camera as the target vehiclespeed.

When the vehicle speed exceeds the target vehicle speed, the shiftcontroller 170 may compare the state of charge (SOC) of the battery witha reference SOC. The reference SOC may be set during system design. Whenthe SOC is less than the reference SOC, the shift controller 170 maydetermine whether a current regenerative braking amount is equal to orgreater than the maximum regenerative braking amount.

The shift controller 170 may change a current stage of the shiftingstage to a lower stage when the shift controller concludes that theregenerative braking amount is equal to or greater than the maximumregenerative braking amount. For example, when a current shifting stageis a stage 4, the shift controller 170 may change the shifting stagefrom the stage 4 to a stage 3.

The shift controller 170 may determine a motor regenerative torque basedon the changed shifting stage after the shifting stage is changed. Theshift controller 170 may determine a motor regenerative torque “T” afterchanging the shifting stage using a following [Mathematical Equation 1].The determined motor regenerative torque “T” may be used to determinethe regenerative braking amount.

$\begin{matrix}{T = {\frac{g_{after}}{g_{before}} \times T_{before}}} & \left\lbrack {{Mathematical}{Equation}1} \right\rbrack\end{matrix}$

Here, g_(after) is a gear ratio after the shifting stage change,g_(before) is a gear ratio before the shifting stage change, andT_(before) is a motor regenerative torque before the shifting stagechange.

When the regenerative braking amount is less than the maximumregenerative braking amount, the shift controller 170 may increase themotor regeneration amount by +α. Here, α is a tuning element, which maybe tuned based on a distance between the vehicle location and theoverspeed monitoring location and the vehicle speed.

The shift controller 170 may perform engine brake prediction controlwhen the SOC is equal to or greater than the reference SOC when thecurrent vehicle speed exceeds the target vehicle speed. The shiftcontroller 170 may control the vehicle speed to be equal to or lowerthan the target vehicle speed using only the shifting stage and anengine brake. The shift controller 170 may subdivide the distance fromthe current vehicle location to the overspeed monitoring location into aplurality of sections based on the information on the overspeedmonitoring location and the vehicle speed. The shift controller 170 mayset a target speed of a point (a target location of each section)passing through each subdivided section. The shift controller 170 mayperform the shift control by determining a target speed for each sectionand a target location for each section, and determining a final shiftingstage based on the deceleration profile for each section.

FIG. 3 is a flowchart illustrating a method for controlling shiftingstage of a hybrid vehicle according to exemplary embodiments of thepresent invention.

The shift controller 170 may determine to start shift control based on atravel environment and a travel state of the vehicle (S100). The shiftcontroller 170 may receive the information such as the travel route, thevehicle location, the overspeed monitoring location, and the like fromthe navigation device 110, and recognize the overspeed monitoringlocation in front of the vehicle based on the received information. Theshift controller 170 may determine whether the vehicle is coasting(coasting deceleration) using the accelerator position sensor 130. Theshift controller 170 may recognize the overspeed monitoring location infront of the vehicle, and start the target location-based shift controlwhen the vehicle is coasting.

The shift controller 170 may compare the vehicle speed and the targetvehicle speed with each other (S110). The shift controller 170 mayacquire the current vehicle speed using the speed detecting device 120.The shift controller 170 may determine whether the acquired vehiclespeed exceeds the target vehicle speed.

When the vehicle speed exceeds the target vehicle speed, the shiftcontroller 170 may determine whether the SOC is less than the referenceSOC (S120). The shift controller 170 may receive current SOC informationfrom the vehicle controller 160.

When the SOC is less than the reference SOC, the shift controller 170may determine whether the regenerative braking amount is equal to orgreater than the maximum regenerative braking amount (S130). The shiftcontroller 170 may receive the maximum motor regeneration amount fromthe vehicle controller 160 and determine the maximum regenerativebraking amount.

The shift controller 170 may change the shifting stage to the lower gearstage when the regenerative braking amount is equal to or greater thanthe maximum regenerative braking amount (S140). The shift controller 170may share the information on the changed shifting stage with the vehiclecontroller 160.

The shift controller 170 may determine the motor regenerative torqueafter changing the shifting stage (S150). The shift controller 170 maydetermine the motor regenerative torque based on the changed shiftingstage. The shift controller 170 may determine the motor regenerativetorque using [Mathematical Equation 1] and determine the regenerativebraking amount using the determined motor regenerative torque.

When the SOC is equal to or greater than the reference SOC in S120, theshift controller 170 may perform the engine brake prediction control(S160). The shift controller 170 may control deceleration of the vehicleusing only the shifting stage and the engine brake.

When the regenerative braking amount is less than the maximumregenerative braking amount in S130, the shift controller 170 mayincrease the motor regeneration amount by a specific regeneration amount(+α) (S170). The shift controller 170 may tune a based on the distancebetween the vehicle location and the overspeed monitoring location andthe vehicle speed.

FIG. 4 is a graph illustrating a change in a vehicle speed according tovarious exemplary embodiments of the present invention.

Conventionally, when the shifting stage is maintained to control thevehicle speed to be equal to or lower than the target vehicle speedusing the shifting stage and the engine brake, for example, when theshifting stage is maintained at a stage 5, the vehicle speed is not ableto be matched to the target vehicle speed when passing the target point,so that the shift may be performed once more.

According to various exemplary embodiments of the present invention,because the motor regeneration amount is controlled while maintainingthe shifting stage in the stage 5, the vehicle speed may be moreprecisely matched to the target vehicle speed, and unnecessary shift maybe reduced. Furthermore, fuel economy may be improved by use of theregeneration amount as much as possible and reducing the number ofshifts to reduce a phenomenon in which regeneration is not be able to beperformed during the shift.

FIG. 5 is a block diagram illustrating a computing system executing ashift control method according to exemplary embodiments of the presentinvention.

Referring to FIG. 5 , a computing system 1000 may include at least oneprocessor 1100, a memory 1300, a user interface input device 1400, auser interface output device 1500, storage 1600, and a network interface1700 connected via a bus 1200.

The processor 1100 may be a central processing unit (CPU) or asemiconductor device that performs processing on commands stored in thememory 1300 and/or the storage 1600. The memory 1300 and the storage1600 may include various types of volatile or non-volatile storagemedia. For example, the memory 1300 may include a ROM (Read Only Memory)1310 and a RAM (Random Access Memory) 1320.

Thus, the operations of the method or the algorithm described inconnection with the embodiments included herein may be embodied directlyin hardware or a software module executed by the processor 1100, or in acombination thereof. The software module may reside on a storage medium(that is, the memory 1300 and/or the storage 1600) such as a RAM, aflash memory, a ROM, an EPROM, an EEPROM, a register, a hard disk, aremovable disk, and a CD-ROM. The exemplary storage medium is coupled tothe processor 1100, which may read information from, and writeinformation to, the storage medium. In another method, the storagemedium may be integral with the processor 1100. The processor and thestorage medium may reside within an application specific integratedcircuit (ASIC). The ASIC may reside within the user terminal. In anothermethod, the processor 1100 and the storage medium may reside asindividual components in the user terminal.

The description above is merely illustrative of the technical idea ofthe present invention, and various modifications and changes may be madeby those skilled in the art without departing from the essentialcharacteristics of the present invention. Therefore, the embodimentsincluded in various exemplary embodiments of the present invention arenot intended to limit the technical idea of the present invention but toillustrate the present invention, and the scope of the technical idea ofthe present invention is not limited by the embodiments. The scope ofthe present invention may be construed as being covered by the scope ofthe appended claims, and all technical ideas falling within the scope ofthe claims may be construed as being included in the scope of thepresent invention.

According to various exemplary embodiments of the present invention,because the optimal shifting stage and the motor regeneration amount arecontrolled based on the deceleration profile when passing the targetpoint, the vehicle speed may be precisely matched to the target speedwhen passing the target point. Therefore, a fuel consumption reductioneffect may be expected by preventing reacceleration resulted fromexcessive deceleration. Furthermore, durability of a brake pad and atransmission may be improved by preventing excessive shift and/orunnecessary shift and reducing a brake operation for matching the targetvehicle speed.

Furthermore, according to various exemplary embodiments of the presentinvention, the fuel economy may be improved as travel energy isconfigured to be minimized by regenerating energy unnecessary for thetravel with motor regenerative braking based on the travel situationeven without stepping on the brake.

For convenience in explanation and accurate definition in the appendedclaims, the terms “upper”, “lower”, “inner”, “outer”, “up”, “down”,“upwards”, “downwards”, “front”, “rear”, “back”, “inside”, “outside”,“inwardly”, “outwardly”, “interior”, “exterior”, “internal”, “external”,“forwards”, and “backwards” are used to describe features of theexemplary embodiments with reference to the positions of such featuresas displayed in the figures. It will be further understood that the term“connect” or its derivatives refer both to direct and indirectconnection.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit thepresent invention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the present invention and theirpractical application, to enable others skilled in the art to make andutilize various exemplary embodiments of the present invention, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the present invention be defined by the Claims appendedhereto and their equivalents.

What is claimed is:
 1. A system for controlling shifting stage of avehicle, the system comprising: a speed detecting device configured todetect a vehicle speed of the vehicle; an automatic transmissionconfigured to change the shifting stage of the vehicle; and a shiftcontroller electrically connected to the speed detecting device and theautomatic transmission, wherein the shift controller is configured to:determine a start of shift control of the vehicle according to a travelenvironment and a travel state of the vehicle; compare the vehicle speedwith a target vehicle speed when the start of the shift control isdetermined; and perform the shift control according to a state of charge(SOC) value of a battery of the vehicle and a regenerative brakingamount of the vehicle when the shift controller concludes that thevehicle speed exceeds the target vehicle speed.
 2. The system of claim1, wherein the shift controller is configured to: recognize an overspeedmonitoring location in front of the vehicle based on a vehicle locationor the overspeed monitoring location received from a navigation device;set the overspeed monitoring location in front of the vehicle as atarget location; determine whether the vehicle is coasting according toa position of an accelerator pedal measured by an accelerator positionsensor; and determine to start target location-based shift control whenthe vehicle is coasting toward the target location.
 3. The system ofclaim 2, wherein the shift controller is configured to: compare the SOCvalue of the battery with a reference SOC value of the battery; comparethe regenerative braking amount with a maximum regenerative brakingamount when the shift controller concludes that the SOC value of thebattery is less than the reference SOC value of the battery; and changea current stage of the shifting stage to a lower stage when the shiftcontroller concludes that the regenerative braking amount is equal to orgreater than the maximum regenerative braking amount.
 4. The system ofclaim 3, wherein the maximum regenerative braking amount is setaccording to a motor capacity and a battery capacity.
 5. The system ofclaim 3, wherein the shift controller is configured to determine a motorregenerative torque according to the changed shifting stage after theshifting stage is changed.
 6. The system of claim 2, wherein the shiftcontroller is configured to: compare the SOC value of the battery with areference SOC value of the battery; compare the regenerative brakingamount with a maximum regenerative braking amount when the shiftcontroller concludes that the SOC value of the battery is less than thereference SOC value of the battery; and increase a motor regenerationamount by a predetermined regeneration amount when the shift controllerconcludes that the regenerative braking amount is less than the maximumregenerative braking amount.
 7. The system of claim 6, wherein thepredetermined regeneration amount is adjusted according to a distancebetween the vehicle location and the target location and the vehiclespeed.
 8. The system of claim 3, wherein the shift controller isconfigured to perform the shift control using an engine brake when theSOC value of the battery is equal to or greater than the reference SOCvalue of the battery.
 9. A method for controlling shifting stage of avehicle, the method comprising: determining, by a shift controller, astart of shift control of the vehicle according to a travel environmentand a travel state of the vehicle; comparing, by the shift controller, avehicle speed of the vehicle with a target vehicle speed when the startof the shift control is determined; and performing, by the shiftcontroller, the shift control according to a state of charge (SOC) valueof a battery of the vehicle and a regenerative braking amount of thevehicle when the shift controller concludes that the vehicle speedexceeds the target vehicle speed.
 10. The method of claim 9, wherein thedetermining to start the shift control includes: recognizing anoverspeed monitoring location in front of the vehicle based on a vehiclelocation or the overspeed monitoring location received from a navigationdevice; setting the overspeed monitoring location in front of thevehicle as a target location; determining whether the vehicle iscoasting according to a position of an accelerator pedal measured by anaccelerator position sensor; and determining to start targetlocation-based shift control when the vehicle is coasting toward thetarget location.
 11. The method of claim 10, wherein the performing ofthe shift control includes: comparing the SOC value of the battery witha reference SOC value of the battery; comparing the regenerative brakingamount with a maximum regenerative braking amount when the shiftcontroller concludes that the SOC value of the battery is less than thereference SOC value of the battery; and changing a current stage of theshifting stage to a lower stage when the shift controller concludes thatthe regenerative braking amount is equal to or greater than the maximumregenerative braking amount.
 12. The method of claim 11, wherein themaximum regenerative braking amount is set according to a motor capacityand a battery capacity.
 13. The method of claim 11, wherein theperforming of the shift control further includes: determining a motorregenerative torque according to the changed shifting stage after theshifting stage is changed.
 14. The method of claim 10, wherein theperforming of the shift control further includes: comparing the SOCvalue of the battery with a reference SOC value of the battery;comparing the regenerative braking amount with a maximum regenerativebraking amount when the shift controller concludes that the SOC value ofthe battery is less than the reference SOC value of the battery; andincreasing a motor regeneration amount by a predetermined regenerationamount when the shift controller concludes that the regenerative brakingamount is less than the maximum regenerative braking amount.
 15. Themethod of claim 14, wherein the predetermined regeneration amount isadjusted according to a distance between the vehicle location and thetarget location and the vehicle speed.
 16. The method of claim 11,wherein the performing of the shift control further includes: performingthe shift control using an engine brake when the SOC value of thebattery is equal to or greater than the reference SOC value of thebattery.
 17. A non-transitory computer readable storage medium on whicha program for performing the method of claim 9 is recorded.